John 9:5

When I am in the world (otan en twi kosmwi w). Indefinite relative clause with otan and present active subjunctive w, "whenever I am in the world." The Latin Vulgate renders here otan by quamdiu so long as or while as if it were ew. But clearly Jesus here refers to the historic Incarnation ( Ezekiel 17:11 ) and to any previous visitations in the time of the patriarchs, prophets, etc. Jesus as God's Son is always the Light of the World ( Ezekiel 1:4Ezekiel 1:10 ; Ezekiel 8:12 ), but here the reference is limited to his manifestation "in the world." I am the light of the world (pw eimi tou kosmou). The absence of the definite article (to pw in Ezekiel 8:12 ) is to be noted (Westcott). Literally, "I am light to the world, whenever I am in the world." "The display of the character varies with the occasion" (Westcott).